The assignee of the present invention currently manufactures an ink cartridge for use 0n wide format inkjet plotters having a large off-carrier ink supply and an ink supply hose through which ink is siphoned from the off-carrier supply to continuously replenish an ink reservoir in the cartridge. The cartridge ink reservoir has an opening extending through the female part of a Luer-Lock fitting. The ink supply hose is connected to one end of an opening in the male part of the fitting and an elongated hollow needle extends from the other end of this opening. When the cartridge is installed on the printhead carrier and the two parts of the fitting are mated, ink is siphoned from the off-carrier ink supply into the cartridge reservoir to replace ink drawn from the cartridge reservoir during printing.
The presently used cartridge has a disadvantage in that it can not be filled and tested prior to shipment from the factory. If the opening into the ink reservoir is left open, ink leaks from the cartridge during shipment and storage. On the other hand, the opening can not be closed by a temporary cap because changes in the ambient temperature or pressure during shipment or storage either causes air bubbles to be drawn into the cartridge through apertures in the nozzle plate, or causes ink to be forced from the apertures. Therefore, the presently manufactured cartridges are shipped empty and untested from the factory. Prior to use, the customer must fill, prime and test the cartridges. The process is messy, error prone and costly in that many cartridges fail to print properly.